Airbrush mechanism



Feb. 2, 1965 J. A. PAASCHE 3,168,250

AIRBRUSH MECHANISM Filed NOV. 24, 1961 5 Sheets-Sheet 1 [95? J0 3% 505 Fi INVENTOR. /Zfi dwae Feb. 2, 1965 J. A. PAASCHE 3,158,250

AIRBRUSH MECHANISM Filed Nov. 24, 1961 3 Sheets-Sheet 3 5 Z4 .9 J54 g 1 3 45 145 :14 J

INVENTOR Jwap United States Patent C 3,168,250 AIRBRUSH MECHANISM Jens A. Paasche, Wilmette, Ill. (1909 Diversey Parkway, Chicago 14, Ill.) Filed Nov. 24, 1961, Ser. No. 154,770 13 Claims. (Cl. 239300) The present invention relates to airbrushes or spray guns and is concerned more specifically with airbrushes which are controlled automatically in response to the pressure of operating air.

One object of the invention is to provide a new and improved airbrush.

Another object is to provide an improved airbrush which is so constructed that components of the airbrush which are subject to contamination by the liquid are confined to an atomizing head which can be readily detached from coacting support and control structure for the head for cleaning and to provide for convenient and eflicient handling of a great variety of fluid materials.

Another object is to provide an airbrush having an improved construction which provides for quick detachment and replacement of an atomizing head, including a liquid control valve, in relation to coacting support and control structure for the head without disassembling of liquid control valve structure in the head or coacting valve operating structure mounted on the support structure for the head.

Another object is to provide in an airbrush of the character recited for the flow of separated streams of atomizing air and fan air through a common bore in the airbrush at high flow rates which are separately controlled at the input end of the bore for high speed coating with heavy materials.

Another object is to provide an airbrush of the above character having an improved construction which provides for a quick uncoupling of a valve needle in a detachable atomizing head from needle valve operating means on support structure for the head as an incident to detachment of the head from the support structure.

Another object is to provide an airbrush of the character recited which will remain sealed against leakage of fluid past control valve operating structure over an extended service life.

Another object is to provide an airbrush controlled in response to the changes in the pressure of operating air and having an improved construction which facilitates mutual alinement and coupling and uncoupling of an air motor from valve actuating means on a detachable atomizing head.

Another object is to provide an improved automatic airbrush requiring no lubrication to serve dependably over an extended service life and remain continuously responsive to changes in operating pressure to be self controlling.

Another object is to provide an airbrush having a new and simplified construction whicth affords advantages in adjusting the atomizing air outlet of the brush.

Another object is to provide an airbrush having an improved and highly compact construction which provides for easy and precise adjustment of the atomizing air flow and the fan air flow independently of each other with independent liquid flow control.

Another object is to provide an improved airbrush of the character recited in the preceding objects which is compact in construction and well adapted for economical manufacture and inherently capable of serving dependably and efficiently in use over a long service life.

Other objects and advantages will become apparent from the following description of the exemplary embodiment of the invention illustrated in the drawings, in which:

FIGURE 1 is a side view of an airbrush forming the exemplary embodiment of the invention;

FIG. 2 is a longitudinal sectional view of the airbrush;

FIG. 3 is a fragmentary longitudinal sectional view on an enlarged scale taken with reference to the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary section view taken generally along the line 44 of FIG. 3;

FIG. 5 is a fragmentary sectional view taken along the line 5-5 of FIG. 2;

FIG. 6 is a fragmentary sectional view showing detailed construction of valve actuating and sealing structure appearing in the medial portion of FIG. 2;

FIG. 7 is an exploded view of a quick release coupling appearing in FIG. 6;

FIG. 8 is a fragmentary sectional view taken along the line 88 of FIG. 6; and

FIG. 9 is a detail view of elements within the quick disconnect coupling.

' Referring to the drawings in greater detail, the airbrush 10 forming the illustrated embodiment of the invention comprises, FIGS. 1 and 2, an atomizing or spray head 12 detachably mounted on a support body 14 which houses valve control and air supply structure for the head.

Spray liquid from a suitable source (not shown) is supplied under pressure to the atomizing or spray head 12 through a spray liquid inlet connection 16 integrally formed on the body 18 of the head 12 and defining an internal liquid inlet passageway 20 communicating with a hollow nozzle support boss 22 projecting forwardly from the center of the head body, as shown. Normally spray fluid is supplied under pressure through the boss 22 to a centrally bored spray nozzle 24 secured to the boss by a retaining nut 26 to project forwardly from the boss, as shown.

The discharge of liquid through the nozzle 24 is controlled by a reciprocable needle valve element 28 coacting with a reduced diameter tip 39 of the nozzle 24 andprojecting rearwardly through a head body bore 32. Retraction of the valve needle 28 opens the nozzle 24 and forward advancement of the needle closes the nozzle. Retraction and advancement of the needle valve 28 to start and stop the outflow of liquid is powered by an air control motor 34 mounted within the lower rear portion of the main body 14 to respond to the pressure of operat- 7 ing air supplied to the airbrush.

As illustrated, operating air from a suitable source (not shown) is supplied through a coupling 36 to an internal air inlet chamber or passage 38 formed within the main body 14 ahead of the motor 34, FIG. 2.

The control motor 34 is formed by a sleeve 40 fitted in the body 14 to define a power cylinder 42 coaxial with the valve needle 28. The cylinder 42 communicates at its forward end with the inlet passage 38 and receives a piston 44 which is encircled by two sealing rings 46 disposed in a circumferential groove 48 and urged radially outward into optimum sealing engagement with the cylinder by a corrugated metal expander ring 50 disposed in the groove 48 behind the ring, as shown in FIGS. 3 and 4.

The rings 46 are advantageously formed of nylon or a polymeric material of similar physical qualities and functions without benefit of lubrication to maintain a good seal between the piston 44 and cylinder 42 over a long service life. The nylon piston rings not only eliminate any need for lubrication, but serve to advantage in avoiding sticking of the piston, which would cause it to fail to respond as intended to changes in operating air pressure applied to the cylinder.

The outer end of the cylinder 42 is covered by a threaded cap 52 supporting adjustable stop structure, to

M be described, for determining the open position of the vawene'aie 28; i i V A coiled compression spring 54 positioned between the cap 52 and piston 44 urges the latter forwardly for closing thenozzle 24. Motion ofthe piston is transmitted V to the nozzle control needle 28 by apiston stem 56 ex st m 6- 'The piston 44 is adjusted along the stem 56 to adjust the residual compression in the spring 54 when the valve needle 28 is in its closed position, thereby adjusting the pressure of the operating air required to move the piston against the spring'and open the nozzle 24.

' The connection between'the forward'end, of the piston stem 5.6 and the needle 28 will be described presently. The rear end ofIth piston stem 56 projects rearwardl y from the piston to coact with an adjustable abutment .64 which determines the open position of the needle 28 and hence the discharge rate of liquid from the nozzle 24. The ahutinent 64 isformed on the forward end of a threaded stem '66" of a liquid adjusting knob 68. The th'readedstem 66 is threaded through a stepped nut 70, which in turn is" threaded onto a hollow boss 72 on the cap, 52. The'nut 70 is tightened firmly on the boss 72 sothat it is'not. loosened by rotation of the knob 68 and the stem 66, which is loosely threaded in the nut 70. controlledfri'ctional resistance to rotation of the knob 68 is pr ovided by a compression spring 74 mounted hetween the nut '70 and the knob, as shown, to apply a friction producing axial force to the stem 66.

The adjusting knob 68 is firmly secured against rotation in its; adjusted position by tightening of an axial screw 73.1 n h knob N ws? U 9 Pointed forwa d e d of the screw, to force a friction plug 80 radially outward through a supporting well 82 in the stem 66 into tight frictional engagement with the central bore '84 within the cap 52 which receives the stem 66. 1

The rotaryposition of the liquid flow adjusting knob 68 is read with reference toja calibrated dial 90 journalled on the nut 70 to permit rotation of the dial into a desired reference position for properly indicating the-position of the knob 68 with reference to the position of the valve needle 28. A corrugated washer 92 exerts an axial force on the dial 190 to effect frictional holding of the dial in the desired rotary position.

As previously intimated, the head 12 is detachably mounted on the body'14. The head is so constructed that all components of the airbrushincluding the valve needle 28, which are subject to contamination by the spray liquid, are removed withthe'head upon detachment of' the-head from theisupport body'l li Upon detachmentof the head 12, the'ivalve needle 28 is disconnected'from the piston stem 56 by operation of: a quick release coupling 94,

which normally connects the valve needle and stem, disposed within a recess :96 formed" in the lowerside 0fthe" body 14 ahead of the air inlet space 38.

The: valve needle 28 and the pist'onfs'tem56' extend i-nto the recess 9.6"an'd are sealed by packing-means which provides advantageously for easy positioning of the valve needleiand' piston stem in mutual coaxial alinement.

- Asshown inFIGI 2, the rear end of the valve needle bore 32 in thespray head body 18 is counterbored and threaded to receive the'for'ward end of a threaded retainingor holding element,9.8.rotatably disposed within a bore IQQformed in the support body 14 and extending for- Wardly to the 'he,ad.12 from the recess 96. Anenl'arged rpta-tinghead 102 on the holding element 98 abuts against the body 14 at the forward end of. the recess 96. The lroldipg -element:98.is axially bored 'to. permit passage therethrough of the valve needle 28 land is counterbored ments 104 to urge'the packing elements forwardly to hold' the packing elements together and effect engagement of the forwardmost one of the elements 104 with the conical bottom of the counterbore in the bore 32 which're: ceives the holding element 98.

The generally conical packing elements 104 are advantageously formed from a yieldable polymeric material, preferably p'olytetrafluoroethylene, sold commercially under the name Teflon.

The sealing elements 104 thus formed will maintain a tight effective seal around the valve needle 28 over a long service life. Any wear on the elements 104 is automatically compensated for by an inward contraction of the elements to continue an eifective seal around the valve needle. In this connection, it will be noted that any liquid which escapes into the space housing the elements 104 operates to apply a squeezing force to the exposed element or elements 104 to enhance the seal around the valve needle.

The piston stem 56 is sealedby a packing unit 112, FIGS. 2 and 6, which provides to advantage for easy location of the stem 56 in precise coaxial al-inement with the valve needle 28. The packing unit 112 is designed to provide for limited radial adjustment of the packing unit in any direction on the support body 14. As shown, the packing unit comprises a generally spool shaped packing capsule formed by a centrally open cap 114 encircling the stern 56'Wlil'li1'l the recess 96 and threaded onto the adjacent end of.a cylindrical element 116 loosely disposed the inletspace 38 and the recess 96.

' The rear end of the element 116 is enlarged to form a radially extending sealing shoulder 120 which bears against an annular gasket 122 to form a seal between the rear end of the element 116 and the body 14. A pin 124 is set in the body 14 and extends into a hole 126 in the shoulder or'flange 120 larger than the pin 124 to' hold the element 116 against rotation upon tightening of the cap 114.

The element 116 is centrally bored to receive the piston stem 56 and is counterbored from its forward end to ac-- commodate a nest of three yieldable polymeric packing elements 128, generally similar to the previously described packing elements 104 used to 'seal the valve needle 28. The extended apicesof theelements 128 point rearwardly in the direction of the air pressure applied to this seal. Acoiledcompression spring 130 disposed between the cap 114 and a spring seat 132 engaging the forwardmost one of the packing elements 128, applies a residual compressive force to the packing elements. The central portionof the spring seat 132 has a conical shape similar to that of the individual packing elements 128. I

As shown, three yieldable polymeric packing elements 128 are used in the packing unit 112, and three yieldable polymeric packing elements 104 are used to form a seal around the valve needle 28.

Freedom of the packing unit 112 to move a limited distance radially is provided by the bore 118 being somewhat larger than the cylindrical element 116 received within the bore 118. This facilitates a radial movement of the forward end of the stem 56 in any direction to have a coaxial alinement with'the valve needle 28, as recited. The forward force of air pressure on the pack: ing unit 112 urges the annular shoulder 120 firmly into engagement with the annular gasket 122 to form an effective seal against the escape of air around the element 116.

The quick disconnect coupling 94 used to connect the forward end of the piston stem 56 to the valve needle 28 comprises an inner sleeve 138, an outer sleeve 140 and an intermediate sleeve 142. The inner sleeve 138 defines a rear series of circumferentially spaced retaining ball apertures 144, which register with an annular groove 146 in the forward end of the piston sleeve 56, and a forward series of circumferentially spaced apertures 148 which register with an annular groove 150 in the rear end of the valve needle 28, FIGS. 6 and 8.

The rear apertures 144 receive a plurality of locking balls 152, FIG. 7, which are normally held by the intermediate sleeve 142 in radially inward positions in which the balls 152 are locked in the stem groove 146. Similarly, a plurality of locking balls 154, FIG. 7, are positioned in the forward apertures 148 and held normally by the intermediate sleeve 142 in inner positions in which the balls 154 lock in the valve needle groove 150.

A compression spring 156 disposed within the outer sleeve 140 between an annular flange 158 on the inner sleeve 138 and a shoulder 160 on the intermediate sleeve 142 urges the intermediate sleeve forwardly to its normal position which is determined by engagement of a forward shoulder 162 on the intermediate sleeve with a snap ring 164 engaging a groove 166 in the inner sleeve 138.

The outer sleeve 140 houses the coupling 94 and includes on its rear end a radially enlarged annular hand grip 168 adapted to be grasped to move the outer sleeve rearwardly. An annular flange 170 on the forward end of the outer sleeve 140 extends radially inward across the forward end of the intermediate sleeve 142, as shown in FIG. 6. This flange forms an abutment confronting the rear end of the head retaining element 98 and coacts with the intermediate sleeve 142 to move the latter rearwardly. The forward end of the inner sleeve 138 stops short of the flange 170.

Rearward displacement of the outer sleeve 140 displaces the intermediate sleeve 142 rearwardly to bring an inner annular groove 172 in the intermediate sleeve into axial alinement with the forward locking balls 154, thus allowing these balls to be cammed radially outward by the valve needle groove 150, to release the valve needle 28 from the coupling 94.

Upon removal of the valve needle 28 from the coupling 94, the locking balls 154 are prevented from dropping out of the apertures 148 in the inner sleeve 138 by an annular lip 180 formed on the inner sleeve 138 at the inner extremity of each ball receiving aperture 148, as shown in FIG. 9.

Normally, the recess 96 in the body 14 is closed by a U-shaped removable cover or shield 182 formed preferably of nylon. The cover 182 is shown in place in FIGS. 1, 2, 6 and 8.

Removal of the cover 182 provides access to the recess 96 for rotating the holding element 98 which moves rearwardly to release the spray head 12. Rearward movement of the element 98 can engage the element 98 with the releasable coupling 94, causing the outer sleeve 140 to move rearwardly to release the valve needle 28. If necessary, hand pressure can be applied to the outer coupling sleeve 141) to move this sleeve rearwardly and release the valve needle 28 for separation of the spray head, including the valve needle, from the components which remain on the body 14.

Fan air and atomizing air are supplied to the spray head 12 in separate streams both of which are caused to flow freely through a common generally longitudinal bore 190, FIG. 2, in the body 14. A short continuation 191 of the bore 190 in the body 14 is formed in the spray head body 18 to register with the body bore 190 and form a part of the body bore upon attachment of the spray head to the body 14.

The full transverse sectional area of the bore 190, except for a relatively small portion used to accommodate a flow dividing sleeve 192, is used in the transmission 6 of atomizing and fan air through the bore to the spray head 12 to provide for maximum air flow efliciency within an airbrush body 14 of minimum size. As will presently appear, the air flows forwardly through the major portion of the length of the bore 190.

The inlet space 38 communicates through an internal passage 194 in the body 14 with an internal chamber 196 through which the bore passes. Rearwardly of the chamber 196, the bore 190 is counterbored to a larger size and threaded as indicated by the number 198.

The rear segment 200 of the sleeve 192 which fits in the enlarged counterbore 198 is also enlarged and is threaded into the counterbore, as shown, so that rotation of the sleeve 192 by means of .a radially enlarged annular hand grip 202, integrally formed on the rear end of the sleeve, causes the sleeve to move axially.

At the forward end of the enlarged sleeve segment 200 the sleeve 192 defines an annular valve element 204, FIG. 5, which coacts with an opposing annular valve seat 206 formed by the body 14 at the juncture of the inner chamber 196 with the forwardly extending portion of the bore 190. The valve element 204 is moved toward and away from the valve seat 206 by rotation of the sleeve 192 in opposite directions and coacts with the seat 206 to regulate or meter the flow of atomizing air from the chamber 196 into an annular flow space 208 extending forwardly through the bore 190, FIGS. 2 and 5, between the wall of the bore and a reduced diameter segment 210 of the sleeve 192 which extends forwardly of the sleeve valve element 204.

The forward end of the sleeve 192 extends into the continuation 191 of the bore 190 in the head 12, and is radially enlarged at its forward end in relation to the reduced diameter sleeve segment 210 to support an annular sealing ring 212 in slidable sealing contact with the bore extension 191.

The sleeve 192 is centrally bored longitudinally and defines internally a longitudinal air passage space 214 extending rearwardly from the forward end of the sleeve to an internal valve seat 216 formed by the sleeve just rearwardly of the sleeve valve element 204, as shown in FIG. 5.

Immediately rearwardly of the valve seat 216, the sleeve 172 defines an internal circular air flow space 218 which is connected through radial apertures 220 in the sleeve with the air chamber 196. The internal valve seat 216 is opposed by a coacting valve element 222 formed on the forward end of a valve stem 224 threaded into the enlarged rear segment 200 of the sleeve 192. Rotation of the stem 224 by means of a control knob 226 integrally formed on the rear end of the stem moves the valve element 222 toward and away from the seat 216 to control or meter the flow of air from the passage 196 into the flow space 210.

The escape of air rearwardly past the stern 224 is advantageously prevented by two nylon sealing rings 230 encircling the stem 224 in sealing engagement with the sleeve 192. A sealing ring 232 encircling the rear sleeve segment 200 in engagement with the body 14 and the previously mentioned annular seal 212 encircling the forward end of the sleeve are also advantageously formed of nylon.

As previously intimated, rotation of the sleeve 192 adjusts the valve element 204 in relation to the seat 206 to control the flow of fan air into the longitudinal air passage space 208. The sleeve 192 is held tightly in any position of adjustment by tightening a lock nut 234 threaded on the sleeve and engaging the body 14, as shown. Rotation of the stem 224 by the knob 226 controls the flow of fan air to the longitudinal air passage space 210. The knob 226 is firmly held in any rotary position of adjustment by tightening of a set screw 236 in the knob 226 against the annular grip element 202 of the sleeve 192. Hence, rotary adjustment of the sleeve 192 after loosening of the lock nut 234 does not disturb,

I nylon.

sage 244 formed in the head body in encircling relation lit to the nozzle support 22 and opening outward in a for-' ward direction.

The forward end of the bore extension 191 connects 7 through a passageway 246 .with an annular passage 24$ encircling the passage 244 inradially spaced relation thereto and opening outwardlyin a forward direction.v

An air cap 259 is' detachably secured-to the forward end of the head body 18 by an annular nut 252 threaded onto the head body 18 and coacting with the air cap to provide for axial adjustment of the air cap in relation to the nozzle tip 3d. An annular lip 254 on the forward end ofthe nut 252 encircles the air cap 250 forward of a radial flange 256 on the rear end of the air cap to hold the air cap against outward displacement, and to form an airtight seal with the fiange 256.

The air cap 250 is shaped to define a hollow boss 258 extending rearwardly in encircling spaced relation to the nozzle 24 to define with the nozzle an annular air passage space 264) communicating with the air supply passage 244 in the head body 18. At the forward end of the boss 258, the air cap 250 defines an inwardly extending annular hp 262 designedto coact with the forward end of the nozzle 30, as shown in FIG. 2, to define anatomizing air' outlet orifice 264.

The boss 258is slidably encircled by a nylon sleeve 266 which has a rear end shaped as shown to sealably engage the forward end of the head body 18 between the passages-244 and 248, and to form a rear seat for a compression spring 27 0, encircling the sleeve 266 between the rear end of the sleeve and the bottom of an annular recess 272 formed in the air cap between the boss 258 and the circumferential periphery of the air cap. The air cap. recess 2'72 opens rearwardly in confronting relation to the annular fan air supply passage 24% in the head body 18. p

Two forwardly extending projections 274 on the air cap 250 are bored to define fan air passages 27o connecting the annular recess 272 with fan air orifices 278.

The rear endof the air cap 250 stops short of the forward end of the head body 18. The space between the air cap and'head body is bridged by the retaining nut 252 and by'the sleeve 266 which is formed to advantage from The spring 27tl holdsthe air cap in tight sealing engagement with the nut 252 and holds the sleeve 266 in sealing engagement with the head body 18 so that the sleeve effectively forms a seal between the air passage space s leading to the atomizing air outlet 264 and the fan air outlets or orifices 278.

The effective size of the atomizing annular air orifice 264 is adjustable by rotation of the nut 252 to effect axial displacement of the air cap 250 which varies the space between the lip 262 and the nozzle structure defining the orifice 264. The spring 270, sleeve 266 and coacting structure maintain the described relationship of the parts for all adjustments of the atomizing air orifice 264. 1

to the atomizing air orifice 264 and the fan air outlets 273. When this operating air supplied to the inlet space 33 reaches a predetermined pressure, the piston 44 auto- :matically opens the nozzle 24 to start the air spray. The nozzle 24 is automatically closed when the air inlet pressure dropsbelow the predetermined operating pressure.

' To cleancontaminated portions of the airbrush, or to change over the airbrush to the spraying of a different liquid, the shield 182 is removed and the retainer-98 and coupling 94 operated to release the head 12 from the body 14 and disconnect the valve needle 28 from the piston stem 56, as described. This can be done quickly and easily and removes all contaminated components of the airbrush.

A clean head is easily positioned on the body 14 and secured in place by tighteningof the retaining element 98. The coupling 94 readily accepts and retains the valve needle 28 of the clean head. A gasket 290 forms a seal between the head 12 and body 14 and a locating pin 222 fixedin the body extends into the head body 13 to aid in orienting the head on the body.

The invention is not necessarily limited to theuse of the structure illustrated but includes the use of alternatives and equivalents within the spirit and scope of the invention as defined by the claims.

The invention is claimed as follows:

1. An airbrush comprising in combination, a body including means defining an inlet air passage, a spray head disposed on the forward end of said body andineluding a nozzle, a centrally bored holding element journalled in said body and threaded into said head to releasably hold the latter on said body, a valve needle reciprocablymounted in said spray head in controlling relation to said nozzle and extending through said hold ing element, packing cones in said holding element encircling said needle, a spring urging said cones together to seal around said needle, means on said body defining a cylinder generally coaxial with said needle and communicating with said air passage, a piston in said cylinder, a piston stem extending from said piston forwardly into proximity to the rear end of said needle, a quick release coupling connecting said stem to said needle and positioned in relation to said holding element to be engaged and released by the holding element as an incident to movement of said holding element to release said head, a packing assembly disposed around said piston stem between said piston and said coupling and including a plurality of packing cones and spring means urging said cones into engagement with each other, said body defining a generally longitudinal bore extending therethrough, said spray head defining a continuation of said bore, said spray head including first orifice means positioned for discharging atomizing air adjacent said nozzle and second orifice meanspositioned for discharging fan air around said nozzle said head defining a first passageway connecting one of said orifice means to the forward end of said bore, said head andsaid body defining a second passageway connecting the other of-said orifice means to said bore a substantial distance rearwardly of the forward endthereof, said bore including an enlarged rear segment thereof,

7 said body defining a first valve seat connected with said The airbrush 10 thus provided can be readily adjusted to provide the optimum desired air spray. Rotation of the knob 68 adjusts the open position of the valve needle 28, and hence the rate of liquid flow from the nozzle 24. Rotation of the nut 252- adjusts the atomizing airorifice 264, as recited. Rotation of the knob 226 adjusts the rate of fan air flow to the outlets 27$, and rotation of the hand grip 202 adjusts the rate of atomizing air to the orifice 264, as recited. Operating air supplied to the inlet space 38 flows through the described air passage spaces inlet m'r passage and encircling said bore immediately forward of sa d enlarged rear segment thereof, a valve sleeve disposed 1n said bore and including a rear segment of relatively large diameter threaded inv the enlarged rear segment of said bore, said sleeve defining an annular valve element opposing said first valve seat, saidsleeve including a segment extending forwardlywithin said bore and having a reduced diameter smaller than said bore, the forward end of said valve sleeve defining an enlarged sealing head fitting slidably in said bore forwardly of the connection thereto of said second passageway whereby said first valve element cooperates with said first valve seat to control the flow of air from said inlet air passage to said other amass orifice means, means for rotating said valve sleeve to adjust said first valve element in relation to said first valve seat, a lock nut for holding said valve sleeve in its adjusted position, said sleeve defining a longitudinal bore extending therethrough and defining internally a second valve seat at the juncture of said reduced diameter forward segment of the sleeve with said relatively large diameter segment thereof, said sleeve defining an air flow connection between said inlet passage and the upstream side of said second seat, a second valve element threaded into said relatively large diameter segment of said sleeve and extending into coacting relation to said second seat to control the flow of air from said inlet passage to said one orifice means, means for rotating said second valve element to adjust the latter in relation to said second valve seat, and means for releasably securing said second valve element nonrotatably to said sleeve.

2. An airbrush comprising in combination, a body including means defining an inlet air passage, a spray head disposed on the forward end of said body and including a nozzle, a centrally bored holding element coacting with said body and threaded into said head to releasably hold the latter on said body, a valve needle reciprocably mounted in said spray head in controlling relation to said nozzle and extending through said holding element, packing means in said holding element encircling said needle, means on said body defining a cylinder alined with said needle and communicating with said air passage, a piston in said cylinder, a piston stem extending from said piston forwardly into proximity to the rear end of said needle, a coupling releasably connecting said stem to said needle, packing means sealably encircling said stem between said piston and said coupling, said body defining a generally longitudinal bore therein, said spray head including first orifice means positioned for discharging atomizing air adjacent said nozzle and second orifice means positioned for discharging fan air around said nozzle, said head defining a first passageway for connecting one of said orifice means to the forward end of said bore, said head and said body defining a second passageway connecting the other of said orifice means to said bore a substantial distance rearwardly of the forward end thereof, said bore including an enlarged rear segment thereof, said body defining a first valve seat having an upstream side communicating with said inlet air passage and having a downstream side communicating with said bore immediately forward of said enlarged rear segment thereof, a valve sleeve disposed in said bore and including a rear segment of relatively large diameter threaded in the enlarged rear segment of said bore, said sleeve defining a valve element coacting with said first valve seat, said sleeve including a segment extending forwardly within said bore and being smaller than said bore to provide for a free flow of air through said bore around said sleeve from said first valve seat to said second passageway, the forward end of said valve sleeve defining an enlarged sealing head fitting slidably in said bore for- Wardly of the connection thereto of said second passageway to block communication between said first valve seat and said first passageway whereby said first valve element cooperates with said first valve seat to control the fiow of air from said inlet air passage to said other orifice means, means for rotating said valve sleeve to adjust said first valve element in relation to said first valve seat, said sleeve defining a longitudinal bore extending therethrough and defining internally a second valve seat located near the forward end of said relatively large diameter segment of the sleeve and communicating at its inlet and outlet sides respectively with said air inlet passage and the forward end of said sleeve bore, a second valve element threaded into said relatively large diameter segment of said sleeve and coacting with said second seat to control the fiow of air from said inlet passage to said one orifice means, and means for rotating said second valve element to adjust the latter in relation to said second valve seat.

3. An airbrush comprising, in combination, a body including means defining an air inlet, a spray head detachably secured to said body and including a nozzle, a reciprocable flow control element mounted in said spray head in flow controlling relation to said nozzle, means on said body defining an air cylinder connected with said air inlet, a piston in said cylinder, means including a releasable coupling for releasably connecting said piston to said flow control element, said body defining a bore therein extending forwardly toward said head, said spray head including means for discharging atomizing air and means for discharging fan air, said head defining a first passageway for connecting one of said air discharge means to the forward end of said bore, said head and said body defining a second passageway for connecting the other of said air discharge means to said bore a substantial distance rearwardly of the connection thereto of said first passageway, said bore including an enlarged rear segment thereof, said body defining a first valve seat having an upstream side communicating with said air inlet and having a downstream side communicating with said bore forward of said enlarged rear segment thereof, a valve sleeve disposed in said bore and including a rear segment threaded in the enlarged rear segment of said bore, said sleeve defining a first valve element coacting with said first valve seat, said sleeve including a segment extending forwardly within said bore and being smaller than said bore to provide for a free flow of air through said bore around said sleeve from said first valve seat to said second passageway, means forming a seal between said bore and the forward end of said sleeve to block communication between said first valve seat and said first passageway whereby said first valve element cooperates with said first valve seat to control the flow of air from said air inlet to said other air discharge means, means for rotating said valve sleeve to adjust said first valve element in relation to said first valve seat, said sleeve defining a longitudinal bore extending therethrough and defining internally a second valve seat located near the forward end of said rear segment of the sleeve and communicating at its inlet and outlet sides respectively with said air inlet passage and with said sleeve bore forward of said second seat, a second valve element threaded into said rear segment of said sleeve and coacting with said second seat to control the flow of air from said air inlet to said one air discharge means, and means for rotating said second valve element to adjust the latter in relation to said second valve seat.

4. An airbrush comprising, in combination, body means including means defining an air inlet, a spray head detachably secured to said body means in a forward position thereon, said spray head including liquid discharge means and a reciprocable fiow control element for said liquid discharge means, packing means encircling said flow control element, means on said body means defining an air cylinder alined with said flow control element and communicating with said air inlet, a piston in said cylinder, a piston stem extending from said piston, a coupling releasably connecting said stem to said flow control element, packing means sealably encircling said stem between said piston and said coupling, said body means defining a bore therein extending forwardly toward said spray head, said spray head including means for discharging atomizing air and means for discharging fan air, said head defining a first passageway for connecting one of said air discharge means to the forward end of said bore, said head and said body means defining a second passageway connecting the other of said air discharge means to said bore a substantial distance rearwardly of the connection thereto of said first passageway, a valve sleeve disposed in said bore, means forming a sliding seal between said bore and said sleeve at a location along the bore between the connections thereto of said first and second passageways, said sleeve including a segment extending rearwardly from said seal between the bore and sleeve to define therewith a first air passage space communicating with said second passageway and extending along said. sleeve rearward-1y away from said spray head,

said sleeve being centrally bored to define a second and internal air passage space communicating through the forward end of said sleeve with said first passageway and extending. along said sleeve, rearwardly away from said spray head, and. means forming two flowcontrol; valves connecting said air inlet withsaid. respective air passage spaces at locations along saidslecve? which are spaced rearwardly from the forwardend of the sleeve.

5. In an airbrush,.the combination of a'body, aspray head, means. detachably connecting, said spray head to said body, flow control: means on, said spray head including a reciprocable control member extending in the direction of said body, anairmotor, disposed on said body and including a piston substantially coaxial with said control member, said body defining an' operating airspace on the spray head: side of said piston, a piston stem connected with said piston and extending'throngh and beyond said air space toward said controlvmember, means releasablyconnecting said piston stem'and said control member, a packing capsule encircling an intermediate portion of said piston stembetween said coupling and said air space, said'body defining a bore therein receiving said capsule and being larger in: transverse. section than said capsule to provide for: limited radial movement or said'capsule in all directions, means providing a circumferential seal between said capsule and saidtbody for different positions of: radial adjustment of said capsule within said bore, andpackingme'ans within: said' capsule forming: a slidable seal between the: capsule, and said piston stem;

6. In an airbrush, the combination .of a body, a spray head, means detachably connecting: said spray head to saidbody, flow control means on said'spray head including a reciprocablecontrol member extending in thexdirection of said body, anair. motor disposed on said body. and including a piston substantially coaxial with said control member, said body defining an operating air spaceonthe spray head side of said'piston, apiston'stem con? nected with said pistonfand' extending. through and beyond said air space into-proximity to the/adjacent end of said control member, coupling means. connecting .said piston stemand. saidcontrolmember, apacking capsule encircling an intermediate portion o-f-said' piston stem between said" coupling and said airspace, said body delining a bore therein receiving said capsule and being:

larger in transverse section than said capsule to provide for limited adjustment of said capsule in all radial d-1rec-- tions, means providing a circumferential seal between said capsule andsaid'body for different positions of radial adjustment of said capsule within said bore, said seal providing means including. an annular sealing shoulder on the air space end of said capsule and threaded means for forcing said shoulder hard toward said body, a plur-ality of flexible polymeric packing elements disposed within-said capsule in encircling sealing relation to said stem, and the central. portion of each of said packing elements having a truncated conical shape the apex of which pointsin the direction of said air space.

7. In an airbrush, the combination of a support, a spray head, means for detachably mounting saidspray head on said: support. to occupy a forward position thereon, flow control means on said spray head including a reciprocable flowcontrol member extending rearwardly from the: spray head, an air motor on said support located rearwardly of'said control member and includinga'piston, said support defining: an internal operating air space disposed forwardly of said'piston, a piston stem connected with said. piston and extending forwardly through and. beyond said air space into proximity to: the rear end. of said fiow control member in generally coaxial relation thereto, means for connecting together said flow control member and said piston stem, and means forming a seal between said stem. and said support forwardly of. said 1?; air space, said last mentioned means including a plurality of flexible polymeric packing elements having conically shaped portions thereof encircling said piston stem to point in the direction of said air space, and springmeans acting on said. packing elements to urge the latter toward said air space.

8. An airbrush comprising, in combination, body means, spray means on the forward end of said body means, said spray means including first air discharge means for discharging. atomizing air and. including second air discharge means for discharging fan air, a fan air flow control valve. and an atomizing air. flow control valve both disposed'on said body. means inv rearwardly spaced relation to said spray. means, said body means defining an air flow bore extending from said valves forwardly toward said spray means, a valve sleeve disposed within said bore and defining within the sleeve a longitudinal bore connected. tov only one of said flow control valves and to one only of said air discharge means to conduct air from said one control valve forwardly through the sleeve bore to saidone air discharge means,

means forming a slidable circumferential seal between said boreand the forwardend of said sleeve, said sleeve including a segment extending rearwardly. of said seal and being smaller than said bore to define therewith an air passage space which is connected to the other only of said valves. and to the. other only of. said air discharge means to conduct air from said other. control valve forwardly through said air passage space to said other air discharge means.

9. In air spray apparatus,.the combination of a first element constituting a support, a movable second element constituting an air cap, holding means coacting with said first and second elements to retain said second element ad- 'justably in an. operative position in relation to said first second element including orifice means shaped to coact with said nozzle and define therewith an air discharge orifice having an. effective size determined by the adjustment of saidsecond element in relation to. said first element, said second. element defining an air discharge outlet separate from said orifice, said first element, defining two air supply passages confronting-said second element,

connecting means for effecting connections of said air supply passages with said air outlet and said air orifice respectively for all operative positions of. adjustment of said second element on said first element within said range of adjustment; said connecting means including two annular partition members sealably related to'said respective elements and being disposed in coaxial mutually telescoped relation for. slidable, telescopic, relative movement in the direction in whichsaid second element is Eld'. justed in relation to said first element; and said holding means and said first and second elements being shaped and dimensioned to provide beyond one end of each of said annular partition. members clearance for free adjustment of said second element throughout said'range of adjustment in said direction Without subjecting, either of said partition members to compression in said one direction.

10. In air spray apparatus, the combination of a first element constituting a support, a movable second element constituting an air cap, holding means coacting withsaid first and second elements to retain said second element.

adjustably in an operative position in relation to said-first element, saidholdingmeans includinga threaded element extending spray nozzle on said first element, said second element including orifice. means shaped to coact with said nozzle and define therewith an air discharge orifice having an effective size determined by the adjustment of said second element in relation to said first element, said second element defining an air discharge outlet separate from said orifice, said first element defining two air supply passages confronting said second element, connecting means for effecting connections of said air supply passages with said air outlet and said air orifice respectively for all operative positions of adjustment of said second element within said range of adjustment; said connecting means including a first annular partition member formed on one of said elements and projecting toward the other of said elements in generally coaxial relation to said nozzle, said connecting means including a second annular partition member disposed in slidable telescoped relation to said first partition member for telescopic movement relative thereto in the direction in which said second element is adjusted in relation to said first element; spring means mounted to urge said second partition member axially into sealing engagement with the other of said first and second elements and to urge said second element to a position on said first element determined adjustably by said threaded element, and said holding means and said first and second elements being shaped and dimensioned to provide beyond one end of each of said annular partition members clearance for free adjustment of said second element throughout said range of adjustment in said direction without subjecting either of said partition members to compression in said one direction.

11. In air spray apparatus, the combination of a support, a movable air cap, holding means coacting with said support and said air cap to hold the latter adjustably in an operative position on said support, said holding means including a threaded element for adjusting said operative position of said air cap toward and away from said support through a substantial range of operative adjustment, an outwardly extending spray liquid nozzle on said support, said air cap including orifice means encircling said nozzle to define therewith an annular air discharge orifice having an elfective size determined by the adjustment of said air cap in relation to said support, said air cap defining an air discharge outlet separate from said orifice, said support defining two air supply passages confronting said air cap, and connecting means for effecting connections of said air supply passages with said air outlet and said air orifice respectively for all operative positions of adjustment of said air cap on said support within said range of adjustment; said connecting means being formed of relatively movable parts shaped to provide for free adjustment of said air cap within said range of adjustment thereof.

12. An airbrush comprising, in combination, body means, means defining on the forward end of said body means a spray nozzle and atomizing air discharge means and fan air discharge means coacting with said nozzle, means for supplying a liquid to said nozzle, said body means defining therein an air supply bore extending forwardly toward said nozzle, a sleeve disposed in said bore and including a forwardly extending longitudinal segment having a size smaller than said bore for defining within said bore around said sleeve a first air supply passage space extending forwardly longitudinally within said bore, said sleeve being centrally bored to define a second air supply passage space therein extending forwardly longitudinally within said bore in isolation from said first air supply passage space, means forming an annular seal between the nozzle end of said sleeve and said bore to isolate the forward ends of said first and second air passage spaces from each other, means defining air passageways connecting the forward ends of said respective air passage spaces with said respective air discharge means, two independent and adjustable air metering valves, said body means defining an air inlet connected to the inlet sides of both said metering valves to supply air thereto under pressure, and the outlet sides of said metering valves being connected to inlet portions of said respective passage spaces located substantial distances from the forward ends of said respective passage spaces so that each passage space receives air only from its associated metering valve and air metered through the valves flows forwardly through said respective passage spaces to said respective air discharge means.

13. In an airbrush, the combination of a body, fan air discharge means located forwardly on said body, atomizing air discharge means located forwardly on said body, said body defining a forwardly extending bore therein, means disposed within said bore to coact with the bore defining portion of the body to form two separated air flow spaces extending forwardly through the bore, means defining separate air passages connecting the forward ends of said respective air flow spaces with said respective air discharge means, air supply means connected to said respective air flow spaces to supply air under pressure to said respective air flow spaces at locations with respect to said bore spaced substantial distances rearwardly of the forward end of said bore so that mutually isolated streams of air flow forwardly through said respective air flow spaces to said respective air discharge means; and two adjustable air metering valves connected in series with said respective air flow spaces to effect independent metering by the metering valves of the two streams of air flowing through the respective air flow spaces, each of which valves serving to pass therethrough only the stream of air which flows through the corresponding air flow space.

References Cited in the file of this patent UNITED STATES PATENTS 2,060,894 Potter Nov. 17, 1936 2,189,644 Wingard Feb. 6, 1940 2,614,793 Storm Oct. 21, 1952 2,708,589 Masek May 17, 1955 2,743,963 Peeps May 1, 1956 2,843,425 Paasche July 15, 1958 2,864,649 Adams Dec. 16, 1958 2,889,134 Bryant June 2, 1959 2,929,566 Paasche Mar. 22, 1960 2,991,940 Dupler et al July 11, 1961 

5. IN AN AIRBRUSH, THE COMBINATION OF A BODY, A SPRAY HEAD, MEANS DETACHABLY CONNECTING SAID SPRAY HEAD TO SAID BODY, FLOW CONTROL MEANS ON SAID SPRAY HEAD INCLUDING A RECIPROCABLE CONTROL MEMBER EXTENDING IN THE DIRECTION OF SAID BODY, AN AIR MOTOR DIPOSED ON SAID BODY AND INCLUDING A PISTON SUBSTANTIALLY COAXIAL WITH SAID CONTROL MEMBER, SAID BODY DEFINING AN OPERATING AIR SPACE ON THE SPRAY HEAD SIDE OF SAID PISTON, A PISTON STEM CONNECTED WITH SAID PISTON AND EXTENDING THROUGH AND BEYOND SAID AIR SPACE TOWARD SAID CONTROL MEMBER, MEANS RELEASABLY CONNECTING SAID PISTON STEM AND SAID CONTROL MEMBER, A PACKING CAPSULE ENCIRCLING AN INTERMEDIATE PORTION OF SAID PISTON STEM BETWEEN SAID COUPLING AND SAID AIR SPACE, SAID BODY DEFINING A BORE THEREIN RECEIVING SAID CAPSULE AND BEING LARGER IN TRANSVERSE SECTION THAN SAID CAPSULE TO PROVIDE FOR LIMITED RADIAL MOVEMENT OF SAID CAPSULE IN ALL DIRECTIONS, MEANS PROVIDING A CIRCUMFERENTIAL SEAL BETWEEN SAID CAPSULE AND SAID BODY FOR DIFFERENT POSITIONS OF RADIAL ADJUSTMENT OF SAID CAPSULE WITHIN SAID BORE, AND PACKING MEANS WITHIN SAID CAPSULE FORMING A SLIDABLE SEAL BETWEEN THE CAPSULE AND SAID PISTON STEM. 